Was given an attitude

I was shopping at the Exact store in ERM, last week. The pregnant lady (she was not wearing a name tag) that was assisting me at the till point had an attitude with me. When I got there I was the one who greeted her. When I left the store after paying, I noticed that she did not remove the hard tag. When I go in other stores it kept on beeping. I had to go back to have it removed. When I got there I told her that she didn't remove a tag I'm some of the items. She just took the plastic bag, took out the items and removed the tag and just handed the bag back to me. She never bothered to even to apologise. She acted as if it was my fault that she did not do her job.